New York, May 8: 'We live in an extreme world,' explains Blair Lazar, a hot sauce creator. 'And I make extreme foods.'

In his hands is the hottest spice in the world, an ultra-refined version of chilli powder so fiery that customers must sign a waiver absolving him of any liability if they are foolish enough to try it.

Locked in a crystal flask sealed with wax and a tiny skull, Lazarís mouth-blistering concoction is pure capsaicin ' the chemical that lends habanero and jalapeno peppers their thermo nuclear heat.

His 16 Million Reserve, which is released to the public this week, is the Holy Grail of hot sauces, the hottest that chemistry can create.

It is 30 times hotter than the spiciest pepper, the Red Savina from Mexico, and 8,000 times stronger than Tabasco sauce. To put the tiniest speck on the tip of your tongue is to experience 'pure heat', Lazar says.

Although capsaicin does not actually burn, it fools your brain into thinking that you are in pain by stimulating nerve endings in your mouth. Some medical experts believe that it could kill an asthmatic or hospitalise a user who touched his eyes or other sensitive parts of the anatomy.

Lazar has trained his palate to endure the sensation, but he remembers the moment he dared to taste his 16 Million Reserve.

'The pain was exquisite,' he said. 'It was like having your tongue hit with a hammer. Man, it hurt. My tongue swelled up and it hurt like hell for days.'

The eye-watering qualities of peppers are measured in internationally-recognised Scoville units, developed by Wilbur Scoville, an American chemist who, in 1912, asked tasters to evaluate how many parts of sugar water it took to neutralise capsaicin heat.

Today, capsaicin content is measured in parts per million, using a process known as high-performance liquid chromatography; one part being equivalent to 15 Scoville units. Benign bell peppers rate zero Scoville units and the Red Savina entered Guinness World Records at 570,000 units.

Pure capsaicin, meanwhile, has a heat score of 16 million units ' inspiring the name for Lazarís latest creation. Each of the 999 limited-edition bottles, priced at $199, contains just a few crystals. The powder is so strong, however, that Lazar estimates that it would have to be dissolved in 250,000 gallons of water before it could no longer be tasted.